In order to increase the number of users utilizing a game, conventionally, various devices are proposed. As a typical example, it is known that a point, an item or the like to be used in a certain game is granted as a bonus to an existing user introducing a new user of the game (for example, see Patent Document 1).
Referring to the Patent Document 1, an introduction relationship (a parent-child relationship) between users, for example, a user B and a user C who are introduced by a user A and start a game, a user D who is further introduced by the user B and starts the game, and the like is managed over a plurality of generations. A bonus point corresponding to game results of a child user and a grandchild user is continuously granted to a parent user.
Referring to the Patent Document 1, moreover, an existing user capable of introducing a game to a new user and acquiring a bonus point is limited to only a user who satisfies a predetermined condition in the game. In other words, an introduction code to be used for introducing a game to another new user is issued to only an existing user satisfying a predetermined condition in the game.
According to the Patent Document 1 having such a structure, the existing user is given a granting point corresponding to a point acquired through the game by a new user introduced by the existing user himself (herself). Moreover, a granting point corresponding to the acquired point is continuously given to the existing user as long as the new user introduced by the existing user himself (herself) continues a custom for playing the game. For this reason, the point granting is not carried out only once but continuously through the introduction by the existing user.
Accordingly, the existing user positively introduce friends or acquaintances in order to acquire a granting point, thereby producing a higher game result. Therefore, it is possible to increase an acquirement efficiency of a new user through an introduction by the existing user. Moreover, the new user introduced by the existing user and starting the game also introduces his (her) friends or acquaintances soon in order to acquire a granting point, thereby generating a higher game result. Therefore, the number of the new users can be increased serially.
Patent Document 1: Japanese Laid-Open Patent Publication No. 2011-83597
The prior art described in the Patent Document 1 provides a mechanism for introducing, to another user, a game (an existing game) that has already been played by the existing user, thereby increasing the number of new users for the existing game. Moreover, the bonus point to be granted to the existing user through the introduction relates to the existing game. For this reason, according to the prior art described in the Patent Document 1, it is possible to produce such advantages as to increase the number of the users for the existing game and to cause the existing user to concentrate on the existing game play more and more.
Referring to the prior art described in the Patent Document 1, however, there is a problem in that the number of the new users cannot be increased for a game other than the existing game. For example, a game maker or a game operating company desires to increase the number of users for a short period of time when a new game is released. If the technique described in the Patent Document 1 is applied to the existing game, however, the number of the users for the existing game can be simply increased and the number of the users for the new game cannot be increased.
If the technique described in the Patent Document 1 is applied to the new game, it is possible to expect the increase in the number of the new users to some degree through an introduction of another user by the new user for the new game. Immediately after the release of the new game, however, since many users are not aware of the release of the new game or are absorbed in the play of the existing game even though they are aware of the release, the number of initial users is increased with difficulty in some cases. Even if the technique described in the Patent Document 1 is applied in that case, it is hard to rapidly increase the number of the new users for the new game.